Additional Safety Considerations >>
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| Requirements
for Safeguards |
Safeguards must meet these minimum
general requirements:
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Prevent contact: The safeguard must
prevent hands, arms, and any other part of a
worker's body from making contact with dangerous
moving parts. A good safeguarding system
eliminates the possibility of of the operator or
another worker placing parts of their bodies near
hazardous moving parts.
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Secure: Workers should not be able
to easily remove or tamper with the safeguard,
because a safeguard that can easily be made
ineffective is no safeguard at all. Guards and
safety devices should be made of durable material
that will withstand the conditions of normal use.
They must firmly be secured to the machine.
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Protect from falling objects: The
safeguard should ensure that no objects can fall
into moving parts. A small tool which is dropped
into a cycling machine could easily become a
projectile that could strike and injure someone.
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Create no new hazards: A safeguard
defeats its own purpose if it creates a hazard of
its own such as a shear point, a jagged edge, or
an unfinished surface which can cause a
laceration. The edges of guards. for instance,
should be rolled or bolted in such a way that they
eliminate sharp edges.
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Create no interference: Any safeguard
which impedes a worker from performing the job
quickly and comfortably might soon be overridden
or disregarded. Proper safeguarding can actually
enhance efficiency as it can relieve the
worker's apprehensions about injury.
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Allow safe lubrication: If possible, one
should be able to lubricate the machine without
removing the safeguards. Locating oil reservoirs
outside the guard, with a line leading to the
lubrication point, will reduce the need for the
operator or maintenance worker to enter the
hazardous area.
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| Training |
Even the most elaborate safeguarding
system cannot offer effective protection unless the
worker knows how to use it and why. Specific and
detailed training is therefore a crucial part of any
effort to provide safeguarding against machine-related
hazards. Thorough operator training should involve
instruction or hands-on training in the
following:
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a description and identification of the hazards
associated with particular machines;
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the safeguards themselves, how they provide
protection, and the hazards for which they are
intended;
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how to use the safeguards and why;
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how and under what circumstances safeguards can
be removed, and by whom (in most cases, repair or
maintenance personnel only); and
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when a lockout/tagout program is
required.
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what to do (e.g., contact the supervisor) if a
safeguard is damaged, missing, or unable to
provide adequate protection.
This kind of safety training is necessary for new
operators and maintenance or setup personnel, when any
new or altered safeguards are put in service, or when
workers are assigned to a new machine or operation.
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| Miscellaneous
Aids |
While these aids do not give complete
protection from machine hazards, they may provide the
operator with an extra margin of safety. Sound judgment is
needed in their application and usage. Examples of possible
application include the following:
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An awareness barrier serves as a reminder to a person
that he or she is approaching the danger area. Although
the barrier does not physically prevent a person from
entering the danger area, it calls attention to it. For
an employee to enter the danger area, an overt act must
take place, that is, the employee must either reach or
step over, under or through the barrier. Generally,
awareness barriers are not considered adequate when
continual exposure to the hazard exists.
Push Stick and Push Block |
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Special hand tools may be used to place or remove
stock, particularly from or into the point of operation
of a machine. A typical use would be for reaching into
the danger area of a press or press brake. A push stick
or block may be used when feeding stock into a saw
blade. When it becomes necessary for hands to be in
close proximity to the blade, the push stick or block
may provide a few inches of safety and prevent a severe
injury.
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| Guard
Construction |
Today many builders of single-purpose
machines provide point-of-operation and power
transmission safeguards as standard equipment.
However, not all machines in use have built-in
safeguards provided by the manufacturer.
Guards designed and installed by the builder offer
two main advantages:
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They usually conform to the design and function
of the machine.
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They can be designed to strengthen the machine
in some way or to serve some additional functional
purposes.
User-built guards are sometimes necessary for a
variety of reasons. They have these advantages:
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Often, with older machinery, they are the only
practical safeguarding solution.
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They may be the only choice for mechanical power
transmission apparatus in older plants, where
machinery is not powered by individual motor
drives.
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They permit options for point-of-operation
safeguards when skilled personnel design and make
them.
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They can be designed and built to fit unique and
even changing situations.
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They can be installed on individual dies and
feeding mechanisms.
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Design and installation of machine safeguards by
plant personnel can help to promote safety
consciousness in the workplace.
User-built guard disadvantages:
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User-built guards may not conform well to the
configuration and function of the machine.
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There is a risk that user-built guards may be
poorly designed or built.
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| Feeding
and Ejection Methods |
Many feeding and ejection methods do not
require the operator to place his or her hands in the danger
area. In some cases, no operator involvement is necessary
after the machine is set up. In other situations, operators
can manually feed the stock with the assistance of a feeding
mechanism. Properly designed ejection methods do not require
any operator involvement after the machine starts to
function.
Using these feeding and ejection methods does not
eliminate the need for guards and devices. Guards and
devices must be used wherever they are necessary and
possible in order to provide protection from exposure to
hazards.
Types of feeding and ejection methods:
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Automatic Feed
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stock is fed from rolls, indexed by machine
mechanism, etc.
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eliminates the need for operator involvement in
the danger area
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other guards are required for operator protection,
usually fixed barrier guards
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requires frequent maintenance
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may not be adaptable to stock variation
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Semiautomatic Feed
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stock is fed by chutes, movable dies, dial feed,
plungers, or sliding bolster
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Automatic Ejection
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work pieces are ejected by air or mechanical means
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may create a hazard of blowing chips or debris
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size of stock limits the use of this method
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air ejection may present a noise hazard
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Semiautomatic Ejection
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work pieces are ejected by mechanical means which
are initiated by the operator
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operator does not have to enter danger area to
remove finished work
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other guards are required for operator protection
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may not be adaptable to stock variation
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Robots
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they perform work usually done by operator
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operator does not have to enter danger area
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are suitable for operations where high stress
factors are present, such as heat and noise
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can create hazards themselves
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require maximum maintenance
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are suitable only to specific operations
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| Machinery
Maintenance and Repair |
Good maintenance and repair procedures
contribute significantly to the safety of the maintenance
crew as well as that of machine operators. The variety and
complexity of machines to be serviced, the hazards
associated with their power sources, the special dangers
that may be present during machine breakdown, and the severe
time constraints often placed on maintenance personnel all
make safe maintenance and repair work difficult.
If possible, machine design should permit routine
lubrication and adjustment without removal of safeguards.
But when safeguards must be removed, and the machine
serviced, the lockout procedure of 29
CFR 1910.147 must be adhered to. The maintenance and
repair crew must never fail to replace the guards before the
job is considered finished and the machine released from
lockout.
In order to prevent hazards while servicing machines,
each machine or piece of equipment should be safeguarded
during the conduct of servicing or maintenance by:
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notifying all affected employees (usually machine or
equipment operators or users) that the machine or
equipment must be shut down to perform some maintenance
or servicing;
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stopping the machine;
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isolating the machine or piece of equipment from its
energy source;
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locking out or tagging out the energy source;
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relieving any stored or residual energy; and
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verifying that the machine or equipment is isolated
from the energy source.
Although this is the general rule, there are exceptions
when the servicing or maintenance is not hazardous for an
employee, when the servicing which is conducted is minor in
nature, done as an integral part of production, and the
employer utilizes alternative safeguards which provide
effective protection as is required by
29 CFR 1910.212 or other specific standards. When the servicing or maintenance is completed, there are
specific steps which must be taken to return the machine or
piece of equipment to service. These steps include:
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inspection of the machine or equipment to ensure that
all guards and other safety devices are in place and
functional,
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checking the area to ensure that energization and
start up of the machine or equipment will not endanger
employees,
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removal of the lockout devices,
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reenergization of the machine or equipment, and
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notification of affected employees that the machine or
equipment may be returned to service.
If it is necessary to oil machine parts while the machine
is running, special safeguarding equipment may be needed
solely to protect the oiler from exposure to hazardous
moving parts. Maintenance personnel must know which machines
can be serviced while running and which can not. The danger
of accident or injury is greatly reduced by shutting off and
locking out all sources of energy.
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